diff --git a/.github/workflows/ironpython.yml b/.github/workflows/ironpython.yml
index 2624d7cb8..515c8f51d 100644
--- a/.github/workflows/ironpython.yml
+++ b/.github/workflows/ironpython.yml
@@ -11,6 +11,12 @@ jobs:
   build:
     name: windows-ironpython
     runs-on: windows-latest
+    env:
+      COMPAS_URL: https://github.com/compas-dev/compas/archive/refs/tags/v2.4.2.tar.gz
+      COMPAS_ROBOTS_URL: https://github.com/compas-dev/compas_robots/archive/a40673d.tar.gz
+      IRONPYTHON_PYTEST_URL: https://pypi.debian.net/ironpython-pytest/latest
+      ROSLIBPY_URL: https://pypi.debian.net/roslibpy/latest
+
     steps:
       - uses: actions/checkout@v2
       - name: Install dependencies
@@ -19,16 +25,16 @@ jobs:
           choco install ironpython --version=2.7.8.1
 
           echo "Downloading ironpython-pytest..."
-          curl -o ironpython-pytest.tar.gz -LJO https://pypi.debian.net/ironpython-pytest/latest
+          curl -o ironpython-pytest.tar.gz -LJO ${{ env.IRONPYTHON_PYTEST_URL }}
 
           echo "Downloading COMPAS..."
-          curl -o compas.tar.gz -LJO https://pypi.debian.net/COMPAS/COMPAS-2.1.0.tar.gz
+          curl -o compas.tar.gz -LJO ${{ env.COMPAS_URL }}
 
           echo "Downloading roslibpy..."
-          curl -o roslibpy.tar.gz -LJO https://pypi.debian.net/roslibpy/latest
+          curl -o roslibpy.tar.gz -LJO ${{ env.ROSLIBPY_URL }}
 
           echo "Downloading compas_robots..."
-          curl -o compas_robots.tar.gz -LJO https://pypi.debian.net/compas_robots/latest
+          curl -o compas_robots.tar.gz -LJO ${{ env.COMPAS_ROBOTS_URL }}
 
           echo "Setting up IronPython environment..."
           ipy -X:Frames -m ensurepip
@@ -38,7 +44,7 @@ jobs:
 
           echo "Installing COMPAS..."
           ipy -X:Frames -m pip install --no-deps compas.tar.gz
-          
+
           echo "Installing roslibpy..."
           ipy -X:Frames -m pip install --no-deps roslibpy.tar.gz
 
diff --git a/requirements.txt b/requirements.txt
index 662a5f52f..e75f48b93 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,4 @@
+# NOTE: Remember to also update the .github/workflows/ironpython.yml file
 compas >= 2.3, < 3
 compas_robots @ git+https://github.com/compas-dev/compas_robots@a40673d
 # compas_robots >= 0.5, < 1